DC Regulator Circuit for Electrosurgical Impedance Response
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Solution Overview
Problem
Prior electrosurgical generator systems face limitations in responsiveness due to the use of two independent control loops, leading to slow response times when dealing with rapidly changing RF output load impedance, which can result in noticeable lag or excessive power delivery during surgical procedures.
Innovation Solution
A DC-to-DC voltage regulator circuit with a pull-up switch and a pull-down switch, along with reactive energy storage elements, is used to manage energy transitions and prevent voltage overshoots, allowing for more precise control of the RF output stage by varying the regulated DC voltage based on impedance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two independent control loops are used to regulate DC voltage and control RF output, then the system can maintain regulated DC voltage and adjust RF output, but the response time to changes in RF load impedance becomes slow
Solution Approach 1:
The patent combines the DC voltage regulation function and RF output control function into a single integrated control loop. The controller simultaneously regulates the DC voltage to a target value and controls the RF output power based on detected tissue impedance, eliminating the delay caused by sequential operation of separate control loops. This merging allows the system to respond immediately to impedance changes while maintaining voltage stability.
2Adaptability or versatility
If iterative control routines are used to adjust target voltage based on RF output load, then the system can adapt to changing tissue impedance, but the response time is limited by the iterative nature of the control
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously detects the actual tissue impedance during the electrosurgical procedure and uses this real-time information to adjust the RF output power and DC voltage target. This closed-loop feedback allows the system to adapt to changing tissue conditions dynamically without the delays associated with iterative control routines, as the adjustment is based on direct feedback rather than repeated trial-and-error cycles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances the responsiveness of the electrosurgical generator system, reducing the risk of unintended tissue damage and maintaining consistent surgical performance by quickly adjusting to changes in tissue impedance, thereby improving surgical flow and precision.
Implementation Method 1
A reactive circuit element is coupled to store energy at a voltage level based upon voltage at an output node
Implementation Method 2
A pull-up switch and a pull-down switch with an output node between them
Implementation Method 3
A first comparator is coupled to cause the pull-up switch to transition between open switch state and its closed switch state based upon a comparison of the pull-up setting voltage and a control voltage
Data Source
AI summary
A DC-to-DC voltage regulator circuit comprising: an output node; a pull-up switch and a pull-down switch with an output node coupled between them; a reactive circuit element coupled to the output node; a pull-up setting voltage circuit coupled to provide a pull-up setting voltage that is a function of a voltage at the output node; a pull-down setting voltage circuit coupled to provide a pull-down setting voltage that is a function of the voltage at the output node; a first comparator coupled to cause the pull-up switch to transition between open switch state and its closed switch state based upon a comparison of the pull-up setting voltage and a control voltage; and a second comparator coupled to cause the pull-down switch to transition between its open switch state and its closed switch state.